Method and system for masking defects within a network

ABSTRACT

A method and system for masking defects within a network are disclosed. In accordance with an embodiment of the present invention, a method for masking defects within a network comprises detecting by a service entity defects within a network. The method further comprises determining a number of detected defects associated with a network component included in the network. The method further comprises generating by the network component a summary alarm if the number of detected defects within the network is greater than a first threshold.

RELATED APPLICATION

This application is related to co-pending U.S. patent application Ser.No. 12/642,285 filed Dec. 18, 2009.

TECHNICAL FIELD

The present invention relates generally to the field of communicationsystems and more specifically to masking individual defects within anetwork generated by a service entity.

BACKGROUND OF THE INVENTION

A communication network typically includes network components thatdetect defects within the network. The network components typicallydetect defects using service entities including Maintenance End Groups(MEG), Service Aware Maintenance End Points (SA-MEP), ServiceTransparent Maintenance End Points (ST-MEP), and Remote MEP, MaintenanceIntermediate Points (MIP). Each network component may include hundredsor even thousands of service entities.

The networking standards 802.1ag and Y.1731 list numerous defect typesand state that these defects should be reported to a network managementsystem. Traditionally all defects are reported as individual defectalarms to the network management system. If each defect is reported asan individual defect alarm, it is possible that thousands of defectalarms are generated either simultaneously or within a very short amounttime.

When masking of the individual defect alarms is not possible, an alarmstorm in the network may occur. Conventional network management systemstypically cannot handle processing the number of individual defectalarms that may be generated during an alarm storm. Even if the networkmanagement system can process each individual defect alarm, handlingsuch a large number of defect alarms may consume many resources in thenetwork.

SUMMARY OF THE INVENTION

In accordance with the present invention, disadvantages and problemsassociated with previous techniques for reporting defects generated by anetwork entity may be reduced or eliminated.

In accordance with an embodiment of the present invention, a method formasking defects within a network comprises detecting by a service entitydefects within a network. The method further comprises determining anumber of detected defects associated with a network component includedin the network. The method further comprises generating by the networkcomponent a summary alarm if the number of detected defects within thenetwork is greater than a first threshold.

In accordance with another embodiment of the present invention, a methodfor masking defects within a network comprises detecting by a serviceentity defects within a network. The method further comprisesdetermining a first number of detected defects associated with a firstnetwork component included in the network. The method further comprisesgenerating by the first network component a first summary alarm if thefirst number of detected defects within the network is greater than afirst upper threshold.

In accordance with another embodiment of the present invention a networkelement comprises a service entity, a first network component includingthe service entity and a processing unit communicatively coupled to thefirst network component. The service entity is configured to detectdefects within a network. The processing unit is configured to determinea first number of defects associated with the first network componentand generate a first summary alarm if the first number of detecteddefects associated with the first network component is greater than afirst upper threshold.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present embodiments and advantagesthereof may be acquired by referring to the following description takenin conjunction with the accompanying drawings, in which like referencenumbers indicate like features, and wherein:

FIG. 1 illustrates a block diagram of a system for reporting defectswithin a network according to teachings of the present disclosure;

FIG. 2 illustrates a flow diagram of a method for generating a summaryalarm in a network according to teachings of the present disclosure; and

FIG. 3 illustrates a flow diagram of a method for reporting defectswithin a network according to teachings of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention and its advantages are bestunderstood by referring to FIGS. 1 through 3, where like numbers areused to indicate like and corresponding parts.

FIG. 1 illustrates an example of a system 100 for reporting defectswithin a network in accordance with certain embodiments of the presentinvention. System 100 may include at least one network component. Anetwork component may be any system, device, or apparatus used in theimplementation of a network. A network component may be a physicaldevice or a device created in software, hardware or a combination ofboth. Further, a network component may contain a plurality of networkcomponents. A network component may be a network element (NE) 102, anetwork interface (NI) 104, a port 106, a service entity 108, a networkmanagement system (NMS) 112, a processing unit 114, a logical interface(LIF) (not expressly shown), or a management controller unit (notexpressly shown).

Each network element 102 may be communicatively coupled to one anothervia a transmission media 110. Each network element 102 may be generallyconfigured to receive data from and/or transmit data to one or moreother network elements 102. In certain embodiments, network element 102may route data received by the network element 102 to another device(e.g., another network element 102) communicatively coupled to thenetwork element 102. Although system 100 is depicted as having twonetwork elements 102, it is understood that system 100 may include anynumber of network elements 102.

As depicted by FIG. 1 each network element 102 may include one or morenetwork interfaces 104. Each network interface 104 may include anysuitable system, apparatus, or device configured to serve as aninterface between a network element 102 and a transmission medium 110.Each network interface 104 may enable its associated network element 102to communicate to other network elements 102 using any suitabletransmission protocol or standard. Network interface 104 and its variouscomponents may be implemented using hardware, software, or anycombination thereof. For example, in certain embodiments, one or more ofnetwork interfaces 104 may include a network interface card. In otherembodiments, one or more network of interfaces 104 may include a linecard.

As depicted in FIG. 1, each of network interfaces 104 may include one ormore physical ports 106. Each physical port 106 may include any system,device or apparatus configured to serve as a physical interface betweena corresponding transmission medium 110 and network interface 104. Insome embodiments, each physical port 104 may include an Ethernet port, aUSB port, a Firewire port or a WiFi transmitter/receiver.

Additionally, a logical interface may be created to represent one ormore ports 106. A logical interface may represent one or more ports suchthat the member ports are represented as a single logical interface. Forexample, a logical interface may be created in network interface 104A torepresent port 106A or port 106B. A logical interface may also becreated in interface 104A to represent both ports 106A and 106B. Alogical interface may be implemented using software, hardware or acombination of both.

As shown in FIG. 1, the ports 106 may include one or more serviceentities 108. Each service entity 108 may be any system, device orapparatus used to detect defects within a network. A service entity 108may detect defects within a network using Service Operations,Administration and Maintenance (SOAM) standards by sending continuitycheck messages (CCM's) and loopback messages (LBM's) over transmissionmedium 110. Examples of service entities 108 may include Maintenance EndGroups (MEG), Service Aware Maintenance End Points (SA-MEP), ServiceTransparent Maintenance End Points (ST-MEP), and Remote MEP, MaintenanceIntermediate Points (MIP).

Each transmission medium 110 may include any system, device or apparatusconfigured to couple corresponding ports 106 of network elements 102 toeach other and communicate information between the corresponding ports106. For example, a transmission medium 110 may include an opticalfiber, an Ethernet cable, a T1 cable, a WiFi signal, a Bluetooth signal,or any other suitable medium.

Defects within a network may occur as network elements 102 receive andtransmit data to other network elements 102. Defects within a networkmay include, but are not limited to, a loss of continuity betweennetwork elements 102, improper network connections between networkelements 102, a loss of signal or a remote defect indication.

Each service entity 108 may be configured to detect defects within anetwork. For example, service entity 108A may send a CCM from port 106Ain network element 102A to port 106A in network element 102B acrosstransmission medium 110A. By sending the CCM, service entity 108A maydetect a loss of continuity or an improper network connection betweennetwork element 102A and network element 102B. If service entity 108Adetects a defect, that defect may be reported to a network managementsystem 112 in the form of an individual defect alarm. Network managementsystem 112 may include any system, device or apparatus configured toreceive defects reported by the service entities 108 within a networkand correct the defects within the network.

There may be thousands of service entities 108 in each network element102 that are configured to detect defects within the network.Consequently, thousands of defect alarms may be simultaneously generatedand reported to network management system 112. When an alarm storm suchas this occurs, network management system 112 may not be able to handlethe large number of alarms. Furthermore, an alarm storm may consume manynetwork resources.

In order to avoid the negative consequences of an alarm storm, a networkcomponent may generate a single summary alarm to report a plurality ofdefects detected by the network component to the network managementsystem 112. In one embodiment, a network component may generate asummary alarm when the number of defects detected by the networkcomponent is greater than a first threshold.

When the number of detected defects is below the first threshold, thenetwork component may report the individual defects to the networkmanagement system 112 in the form of individual defect alarms.

A processing unit 114 may be configured to generate a summary alarmassociated with a network component. Processing unit 114 may also beconfigured to monitor the number of defects that have been reported bythe network components in order to determine the total number of defectsdetected within the network. Processing unit 114 may also be configuredto determine the total number of defects detected by an individualnetwork component. Processing unit 114 may further be configured toreport individual defects to the network management system by generatingindividual defect alarms associated with network components.

The processing unit may be included within various network components.For example, a network element 102, a network interface 104, a port 106,a service entity 108, or a management control unit may include aprocessing unit.

Each individual component may include a processing unit configured todetermine the number of defects detected, generate individual defectalarms or generate summary alarms associated with that component.

For example, a network element 102A may contain network interfaces 104Aand 104B, and network interface 104A may contain a logical interface.The logical interface may contain ports 106A and 106B, and port 106A maycontain a service entity 108A. Network element 102A, network interfaces104A and 104B, the logical interface, ports 106A and 106B, and serviceentity 108 may all include a processing unit 114 communicatively coupledto each respective network component. Each processing unit 114 may alsoconfigured to generate individual defect alarms, generate summaryalarms, or determine the number of defects detected associated with eachrespective network component.

Additionally, a processing unit contained in one network component maygenerate a summary alarm or individual defect alarm associated withanother network component. For example, network element 102A may containprocessing unit 114A. Network element 102A may also contain networkinterfaces 104A and 104B, network interface 104A may contain ports 106Aand 106B, and port 106A may contain service entity 108A. Processing unit114A may be communicatively coupled to network interface 104A.Processing unit 114A may be configured to determine the number ofdefects detected by network interface 104A and generate a summary alarmassociated with network interface 104A, even though network interface104A may not contain processing unit 114A.

Further, processing unit 114A may generate an individual defect alarmassociated with network interface 104A. Service entity 108A may detect adefect, and processing unit 114A may be communicatively coupled toservice entity 108A. Processing unit 114A may generate an individualdefect alarm associated with service entity 108A. The individual defectalarm would also be associated with network interface 104A becausenetwork interface 104A contains service entity 108A.

One or more processing units 114 may perform the functions illustratedherein. In one embodiment, one processing unit 114 may determine thenumber of defects detected within a network and another processing unit114 may generate the summary alarm, while another processing unit 114may generate individual defect alarms. In another embodiment, a singleprocessing unit 114 may perform all the functions. Processing unit 114may be any implementation of hardware, software or combination of bothused to perform calculations or generate commands within the network.

As the defects are corrected by the network management system 112, thenumber of defects detected by the network component may be reduced. Whenthe number of defects detected by the network component is less than asecond threshold, the summary alarm may be cleared and the networkcomponent may resume sending the individual defect alarms to the networkmanagement system 112. Processing unit 114 may be configured to clearthe summary alarm.

The same network component that detects the defects may generate andclear the summary alarm. Additionally, one network component may detectdefects within a network, while another network component generates andclears the summary alarm associated with the network component thatdetects the defects.

For example, network element 102A may generate a summary alarmassociated with network interface 104A if network interface 104A detectsa number of defects greater than a first threshold associated withnetwork interface 104A. In certain embodiments, the first thresholdassociated with network interface 104A may be between approximatelyfifty (50) and sixty (60).

Network element 102A may clear the summary alarm generated for networkinterface 104A if the number of defects detected by network interface104A is less than a second threshold associated with network interface104A. In certain embodiments, the second threshold associated withnetwork interface 104A may be between approximately thirty (30) andforty (40). Additionally, network interface 104A may generate and cleara summary alarm associated with network interface 104A.

System or network 100 may also include one or more network componenthierarchal levels. A first network component may include one or morenetwork components within the first network component. Additionally, oneor more network components within the first network component maycontain one or more network components. For example, as illustrated inFIG. 1, system or network 100 may include network elements 102A and102B, network management system 112 and a processing unit (not expresslyshown). Network elements 102A and 102B may include network interfaces104A and 104B, network interfaces 104A and 104B may include a logicalinterface, the logical interface may include ports 106A and 106B, andports 106A and 106B may include one or more service entities 108. Thus,the network elements 102 may be considered to be the highest level andthe service entities 108 may be considered to be the lowest level withinthe hierarchy.

One or more network components may be configured to generate a summaryalarm associated with each network component within the networkcomponent hierarchal levels. One or more network components may also beconfigured to generate one or more individual defect alarms associatedwith each network component within the network component hierarchallevels.

In one embodiment, the generation and clearing of one or more summaryalarms associated with the network components within the network may beprioritized. In one embodiment, the system 100 may prioritize thesummary alarms based on the hierarchy within the system 100 such thatwhen a summary alarm is generated in a higher level, any summary alarmsin a lower level included in the higher level may be cleared. Forexample, a summary alarm may be generated for a network interface 104Awhen the number of defects detected is above a first thresholdassociated with network interface 104A. If a summary alarm waspreviously generated for either of ports 106A or 106B, the port summaryalarm will be cleared when the network interface summary alarm isgenerated. Additionally, any individual defect alarms generated byservice entities 108 will be cleared when a port summary alarm isgenerated.

FIG. 2 illustrates a flow diagram of a method for generating a summaryalarm in a network. The method in FIG. 2 illustrates a prioritization ofsummary alarms associated with network components according to networkhierarchal levels.

In the particular embodiment illustrated by FIG. 2, a network componentmay generate a summary alarm associated with one or more networkcomponents within one or more network hierarchal levels. The firstnetwork component may be a network interface included in a networkelement, with the network element being in a first hierarchical level.The network interface may include one or more ports represented by oneor more logical interfaces. The one or more logical interfaces may be ina second hierarchal level that is below the first hierarchal levelbecause the network interface contains the one or more logicalinterfaces. Also, the one or more logical interfaces may contain one ormore service entities. The one or more service entities may be in athird hierarchal level that is below the first and second hierarchallevels because the network interface may contain the one or more logicalinterfaces that contain the one or more service entities.

According to the embodiment in FIG. 2, network components detect defectswithin the network at step 200. In this particular embodiment, thenetwork interface is the highest level and the service entity is thelowest level. In other embodiments, other network components may beincluded in the hierarchy either above or below the network interface.

At step 202 a network component determines if a network interface withina network element should be processed. If a particular network interfaceshould be processed, the method moves to step 204. In one embodiment,network components may be processed by determining if the serviceentities within the network components have detected defects. If nonetwork components need to be processed, the method returns to step 200.

At step 204, a network component determines whether the number ofdefects detected by the network interface is greater than a firstthreshold associated with the network interface. The first thresholdassociated with the network interface may be a Network Interface HighWatermark (NI_WM_HI), which may be a number between approximately fifty(50) and approximately sixty (60). If the number of defects detected bythe network interface is greater than the network interface highwatermark, a network component may generate a summary alarm associatedwith the network interface at step 206.

When the network component generates the summary alarm associated withthe network interface, the network component also clears any summaryalarms associated with any network components in a lower hierarchicallevel included within the network interface (e.g., the logicalinterfaces within the network interface). For example, a networkcomponent may have generated a summary alarm associated with a logicalinterface within the network interface. When the network componentgenerates the summary alarm for the network interface, the networkcomponent also may clear the summary alarm for the logical interfacewithin the network interface.

When the network component generates the summary alarm associated withthe network interface, it may also clear any individual defect alarmsassociated with the network interface. For example, the networkinterface may contain a logical interface and the logical interface mayinclude a service entity. The service entity may have detected a defectwithin the network and a network component may have generated anindividual defect alarm associated with the service entity. Because theservice entity is included in the logical interface and the networkinterface, the defect alarm associated with the service entity is alsoassociated with the logical interface and the network interface.Therefore, when the network clears the individual defect alarmsassociated with the network interface, the network component may clearthe defect alarm associated with the service entity contained in thenetwork interface.

Following step 206, the method returns to step 202. A network componentmay again determine if a network interface or group of networkinterfaces needs to be processed at step 202.

Returning to step 204, if the number of defects detected by the networkinterface is less than or equal to the Network Interface High Watermark,the method moves to step 208 where a network component may determine ifthe number of defects detected by the network interface is less than asecond threshold associated with the network interface. The secondthreshold associated with the network interface may be a NetworkInterface Low Watermark (NI_WM_LO). The Network Interface Low Watermarkmay be a number between approximately thirty (30) and forty (40). Thevalues of the Network Interface High Watermark and the Network InterfaceLow Watermark may vary greatly according to different networkimplementations, requirements, and capabilities.

At step 208, if the number of defects detected by the network interfaceis less than the Network Interface Low Watermark, the method moves tostep 210. At step 210, a network component may clear the summary alarmassociated with the network interface, and the method moves to step 212.After a summary alarm is generated, a network component may correctdefects detected by a network interface. As such, the network componentmay clear these summary alarms if the number of defects detected by thenetwork interface or group of network interfaces is reduced. At step208, if the number of defects detected by the network interface isgreater than or equal to the Network Interface Low Watermark, the methodskips step 210 and moves to step 212.

At step 212 a network component may determine if any logical interfaceswithin the network interface should be processed. If a logical interfaceshould be processed, the method moves to step 214. In one embodiment,network components may be processed by determining if the serviceentities within the logical interfaces have detected defects. If nological interfaces need to be processed, the method may return to step202.

At step 214, a network component may determine if the number of defectsdetected by the logical interface is greater than a first thresholdassociated with the logical interface. The first threshold associatedwith the logical interface may be a Logical Interface High Watermark(LIF_WM_HI).

The Logical Interface High Watermark may be a number that is lower thanthe Network Interface High Watermark of the network interface thatcontains the logical interface. Therefore, a network component maygenerate a summary alarm for a logical interface within a networkinterface at times when the number of defects detected by the networkinterface may not trigger a summary alarm associated with the networkinterface. For example the Network Interface High Watermark may be anumber between approximately fifty (50) and sixty (60) and the LogicalInterface High Watermark may be a number between twenty (20) and (30).

If the number of defects detected by the logical interface is greaterthan the Logical Interface High Watermark, the method may move to step216 where a network component may generate a summary alarm associatedwith the logical interface being processed. When the network componentgenerates a summary alarm for the logical interface, the networkcomponent may also clear any individual defect alarms associated withthe logical interface. After step 216, the method may return to step212.

If the number of defects detected by the logical interface is notgreater than the Logical Interface High Watermark, the method may movefrom step 214 to step 218. At step 218, a network component determinesif the number of defects detected by the logical interface is less thana second threshold associated with the logical interface. The secondthreshold associated with the logical interface may be a LogicalInterface Low Watermark (LIF_WM_LO).

The value of the Logical Interface Low Watermark may be a value lessthan the Logical Interface High Watermark, and may depend on variousfactors including the number of ports represented by the logicalinterface and the number of service entities associated with each portwithin the logical interface. For example, the Logical Interface HighWatermark may be a number between approximately twenty (20) and thirty(30) and the Logical Interface Low Watermark may be a number betweenapproximately ten (10) and twenty (20). The values of the LogicalInterface High Watermark and the Logical Interface Low Watermark mayvary greatly according to different network implementations,requirements, and capabilities.

If the number of defects detected by the logical interface is less thanthe Logical Interface Low Watermark, the method may move to step 220. Atstep 220, a network component may clear a summary alarm associated withthe logical interface and the method moves to step 222. If the number ofdefects detected by the logical interface is greater than or equal tothe Logical Interface Low Watermark, the method skips step 220 and movesfrom step 218 to step 222.

At step 222, a network component determines if any service entitieswithin the logical interface should be processed. If no service entitieswithin the logical interface should be processed, the method moves fromstep 222 to step 202. If a service entity within the logical interfacedoes need to be processed, the method moves from step 222 to step 224.

At step 224, a network component determines if a service entity hasdetected a defect. If a service entity has detected a defect, the methodmoves from step 224 to step 226 where a network component may generatean individual defect alarm associated with the service entity thatdetected the defect. The individual defect alarm may be used report thedefect within the network to a network management system. After step226, the method returns to step 222.

Returning to step 224, if a network component determines that theservice entity has not detected a defect in the network, the methodmoves from step 224 to step 228. At step 228 a network component mayclear an individual defect alarm that may be associated with the serviceentity. For example, a service entity may have detected a defect withinthe network and generated an individual defect alarm associated withthat entity. The defect detected by the entity may have been corrected,and the entity may no longer detect any defects. A network component maynow clear the individual defect alarm associated with that entity.Following step 228 the method returns to step 222.

Although the method illustrated by FIG. 2 has been described withspecific network components, other components may be used to carry outthe steps illustrated therein.

FIG. 3 illustrates a method for reporting defects detected within anetwork using a summary alarm. In typical network systems, when a defectis detected and a defect alarm is generated, the defect is automaticallyreported to a network component (e.g., a network management system(NMS)) without any action by the network management system itself. Asdescribed above, an alarm storm can greatly limit the resourcesavailable to a network management system. It may be advantageous notonly to generate a summary alarm, but to have the network managementsystem generate a request to the network elements for the defectsinstead of having the defects automatically reported to the networkmanagement system.

In FIG. 3 a network element (NE) 102 is depicted as beingcommunicatively coupled to a network management system (NMS) 112.Network element 102 is depicted as generating a summary alarm and anetwork management system (NMS) 112 is depicted as receiving the summaryalarm. Although the method in FIG. 3 is depicted as such, a plurality ofnetwork components configured to carry out the steps in FIG. 3 may beused.

As illustrated in FIG. 3, network element 102 may generate a summaryalarm if the number of detected defects is greater than a firstthreshold, and network element 102 may send the summary alarm to networkmanagement system 112 at step 300. At step 302, network managementsystem 112 may save a first timestamp upon receiving the summary alarm.The first timestamp may give network management system 112 and networkelement 102 a reference of when the summary alarm was generated.Although network management system 112 is depicted as saving the firsttimestamp, network element 102 or another network component may alsosave the first timestamp.

After sending the summary alarm to network management system 112,network element 102 may receive a request from network management system112 for the detected defects within the network at step 306. Networkmanagement system 112 may send the request in response to the summaryalarm. At step 308, network element 102 reports the detected defects tonetwork management system 112 in response to the request from networkmanagement system 112.

After network element 102 sends the summary alarm to network managementsystem 112, changes may occur in the defects within the network. Achange in the network may be an additional defect being detected withinthe network. Another change may be a defect in the network beingcorrected. Network management system 112 may need to be notified that achange may have occurred in the defects within the network after thesummary alarm is generated so that network management system 112 canproperly attend to the network. It may be advantageous for networkmanagement system 112 and network element 102 to have a reference ofwhen the summary alarm was generated.

To facilitate tracking changes in defects within the network, networkelement 102 may also start a first transient condition timer at step 304upon sending the summary alarm at step 300. While the first transientcondition timer is running, network element 102 may detect a change inthe defects within the network at step 310. For example, aftergenerating the summary alarm, network element 102 may have detectedanother defect within the network. As another example, after receivingthe summary alarm, network management system 112 may have corrected adefect within the network, therefore causing a defect alarm associatedwith network element 102 to be cleared. Both of these events may bechanges in the network that occurred after the summary alarm wasgenerated.

After the first transient condition timer expires in step 312, networkelement 102 may generate a first transient condition and send the firsttransient condition to network management system 112 in step 314.Network element 102 may generate the first transient condition toindicate that a change in the defects within the network has occurredafter the summary alarm was generated.

In response to the first transient condition, network element 102 mayreceive a request from network management system 112 for a change in thedefects within the network after the summary alarm was generated.Network management system 112 and network element 102 may use the firsttimestamp saved at step 302 as a reference to indicate when the summaryalarm was generated. Therefore, network element 102 may receive arequest from network management system 112 for the change in defectswithin the network that have occurred since the first timestamp at step320. Network element 102 may report the change in defects within thenetwork since the first timestamp at step 322. Because the firsttimestamp may be associated with the summary alarm, network element 102may report the change in defects within the network that occurred afterthe summary alarm was generated by reporting the change in defectswithin the system since the first timestamp.

Network management system 112 may save a second timestamp at step 316,after receiving the first transient condition. The second timestamp maybe saved to indicate when network management system 112 last received anupdate on changes in defects within the network (e.g., to indicate whenthe first transient condition occurred).

Additionally, network element 102 may generate a first transientcondition after the first transient condition timer expires withoutdetermining if a change in defects within the network has occurred sincethe first transient condition timer was started. Network element 102 maygenerate the first transient condition to indicate to network managementsystem 112 that network management system 112 may need to request thechange in defects within the network after receiving the summary alarm.

In another embodiment, network management system 112 may start a firsttransient condition timer upon receiving the summary alarm. When thefirst transient condition timer generated by network management system112 expires, network management system 112 may request the changes indefects within the networks after the first transient condition timerwas started, which may correspond with when the summary alarm wasgenerated. In this particular embodiment, network management system 112may start a second transient condition timer after the first transientcondition timer expires. Network management system 112 may save a secondtimestamp associated with when the first transient condition timerexpires. The second timestamp may be used as a reference to indicate tonetwork management system 112 when it last checked for a change indefects.

Returning now to step 318, after the first transient condition timerexpires at step 312, a second transient condition timer may start atstep 318. At step 324, the second transient condition timer expires. Nochanges in the defects within the network may have occurred from thetime the second transient condition timer started and expired. In oneembodiment, as illustrated in step 324, network element 102 may notgenerate a transient condition because no changes occurred.

In another embodiment, network element 102 may send a second transientcondition to network management system 112 to prompt network managementsystem 112 to request an update in the change in defects since the firsttransient condition. Upon receiving the request, network element 102 maysend network management system 112 a report indicating that no changesin defects have occurred since the first transient condition.

Returning to step 326, network element 102 may start a third transientcondition timer after the second transient condition timer expires. Atstep 328, network element 102 may detect that one or more defects havebeen corrected. The number of defects may be lower than a secondthreshold and network element 102 may clear the summary alarm. Networkelement 102 may send a clear summary alarm signal to network managementsystem 112 at step 330.

At step 332, network element 102 may generate a second transientcondition because a change (e.g., clearing the summary alarm) in thedefects within the network has occurred after the first transientcondition was generated. A second timestamp associated with the firsttransient condition may have been saved at step 316. Therefore, networkelement 102 may generate a second transient condition because a changein the defects within the network has occurred since the secondtimestamp.

Network element 102 may receive in response to the second transientcondition a request from network management system 112 for the change indefects since the second timestamp at step 336. At step 338, networkelement 102 may report to network management system 112 the change indefects within the network since the second timestamp. At step 334, thethird transient condition timer may be stopped.

Certain embodiments of the invention may provide one or more technicaladvantages, including the ability to mask multiple defects within anetwork by generating a single summary alarm when the number of defectsis above a threshold. By reducing the number of alarms that need to bemaintained and reported, the resources dedicated to defect reporting andservicing may be reduced.

Another advantage may be that a first network component (e.g., a networkmanagement system) may request a report of the defects within thenetwork instead of a second network component (e.g., a network element)proactively reporting defects to the first network component. A networkmanagement system may better control its use of resources by requestingdefect reports instead of having defects proactively pushed to thenetwork management system by a network element.

Although this disclosure has been described in terms of certainembodiments, alterations and permutations of the embodiments will beapparent to those skilled in the art. Accordingly, the above descriptionof the embodiments does not constrain this disclosure. Other changes,substitutions and alterations can be made herein without departing fromthe spirit and scope of the invention as defined by the followingclaims.

What is claimed is:
 1. A method for masking defects within a network,comprising: detecting by a plurality of service entities defects withina network, the plurality of service entities included in a networkcomponent of the network, each service entity generating a defect alarmto the network component, wherein the network component is includedwithin a network element that comprises network interfaces, each networkinterface comprises a logical interface, each logical interfacecomprises ports, and each port comprises one or more of the plurality ofservice entities, wherein at least one of the ports is coupled toanother port of another network element via a transmission medium;determining by the network component a number of defects detected by theservice entities included in the network component; generating by thenetwork component a summary alarm if the number of detected defectswithin the network is greater than a first threshold, the summary alarmrepresenting the defect alarms generated by the service entities; andclearing by the network component the defect alarms generated by theservice entities if a summary alarm is generated.
 2. The method of claim1, further comprising clearing by the network component the summaryalarm if the number of defects is less than a second threshold.
 3. Themethod of claim 2, wherein the first threshold is greater than thesecond threshold.
 4. The method of claim 1, wherein the networkcomponent comprises a network element, a network interface, a logicalinterface or a port.
 5. A method for masking defects within a network,comprising: detecting by a plurality of service entities defects withina network, the plurality of service entities included in a first networkcomponent of the network, each service entity generating a defect alarmto the first network component, wherein the first network component isincluded within a network element that comprises network interfaces,each network interface comprises a logical interface, each logicalinterface comprises ports, and each port comprises one or more of theplurality of service entities, wherein at least one of the ports iscoupled to another port of another network element via a transmissionmedium; determining by the first network component a first number ofdefects detected by the service entities included in the first networkcomponent; generating by the first network component a first summaryalarm if the first number of detected defects within the network isgreater than a first upper threshold, the first summary alarmrepresenting the defect alarms generated by the service entities; andclearing by the first network component the defect alarms generated bythe service entities if a first summary alarm is generated.
 6. Themethod of claim 5, further comprising clearing by the first networkcomponent the first summary alarm if the first number of defects is lessthan a first lower threshold.
 7. The method of claim 5, furthercomprising: generating an individual defect alarm by the first networkcomponent for each of the detected defects; and clearing each individualdefect alarm when the first summary alarm is generated.
 8. The method ofclaim 5, further comprising: determining a second number of detecteddefects associated with a second network component that includes thefirst network component; generating a second summary alarm associatedwith the second network component if the second number of detecteddefects associated with the second network component is greater than asecond upper threshold for the second network component; and clearingthe first summary alarm associated with the first network component whenthe second summary alarm is generated.
 9. The method of claim 8, furthercomprising clearing by the second network component the second summaryalarm if the second number of defects is less than a second lowerthreshold.
 10. The method of claim 9, wherein: the second upperthreshold is approximately twice the first upper threshold; and thesecond lower threshold is approximately twice the first lower threshold.11. The method of claim 8, further comprising: generating an individualdefect alarm by the second network component for each of the detecteddefects; and clearing each individual defect alarm when the secondsummary alarm is generated.
 12. A network element, comprising: aplurality of service entities configured to detect defects within anetwork and generate a defect alarm; a first network component includingthe service entities, each service entity generating a defect alarm tothe first network component, wherein the first network component isincluded within a network element that comprises network interfaces,each network interface comprises a logical interface, each logicalinterface comprises ports, and each port comprises one or more of theplurality of service entities, wherein at least one of the ports iscoupled to another port of another network element via a transmissionmedium; and a processing unit communicatively coupled to the firstnetwork component, the processing unit configured to: determine a firstnumber of defects detected by the service entities included in the firstnetwork component; generate a first summary alarm if the first number ofdetected defects associated with the first network component is greaterthan a first upper threshold, the summary alarm representing the defectalarms generated by the service entities; and clear the defect alarmsgenerated by the service entities if a summary alarm is generated. 13.The network element of claim 12, wherein the processing unit is furtherconfigured to clear the first summary alarm if the first number ofdetected defects associated with the first network component is lessthan a first lower threshold.
 14. The network element of claim 12,wherein the processing unit is further configured to: receive detecteddefects from the service entity; generate an individual defect alarm foreach of the detected defects; and clear each individual defect alarmwhen the first summary alarm is generated.
 15. The network element ofclaim 12, further comprising a second network component including thefirst network component and communicatively coupled to the processingunit.
 16. The network element of claim 15, wherein: the first networkcomponent comprises a logical interface; and the second networkcomponent comprises a network interface.
 17. The network element ofclaim 15, wherein the processing unit is further configured to:determine a second number of defects associated with the second networkcomponent; generate a second summary alarm associated with the secondnetwork component if the second number of detected defects associatedwith the second network component is greater than a second upperthreshold for the second network component; and clear the first summaryalarm associated with the first network component when the secondsummary alarm is generated.
 18. The network element of claim 17, whereinthe processing unit is further configured to clear the second summaryalarm if the second number of defects is less than a second lowerthreshold.
 19. The network element of claim 18, wherein: the secondupper threshold is approximately twice the first upper threshold; andthe second lower threshold is approximately twice the first lowerthreshold.
 20. The network element of claim 17, wherein the processingunit is further configured to: receive detected defects from the serviceentity; generate an individual defect alarm for each of the detecteddefects; and clear each individual defect alarm when the second summaryalarm is generated.